1.Prenatal diagnosis of 22q11.2 microduplication syndrome in a three-generation family: Clinical-genetic characteristics and literature review.
Yifan LIAO ; Yidong WEN ; Xiaoqin DENG ; Cimo WANG ; Zhirong SHANG ; Jinghong YANG ; Jiabing LI
Chinese Journal of Medical Genetics 2026;43(1):57-63
OBJECTIVE:
To explore the genetic etiology for a pregnant woman with a history of multiple adverse pregnancies and assess the phenotype-genotype correlation of 22q11.2 microduplication syndrome in her family.
METHODS:
Amniotic fluid sample was taken from a pregnant woman for whom non-invasive prenatal screening indicated chromosome 22 abnormalities in the fetus. Peripheral blood samples from the woman, her brother and parents were collected for high-throughput low-depth whole genome sequencing (CNV-seq). A pedigree traceability analysis of the results was conducted in conjunction with analysis of clinical manifestation. Relevant literature (from establishment to March 2025) was systematically searched. This study was approved by the Medical Ethics Committee of Mianyang Maternal and Child Health Care Hospital (Ethics No.: Lun Shen [2024]009).
RESULTS:
CNV-seq revealed that the fetus had harbored a 6.02 Mb duplication at 22q11.21q11.23. Karyotyping confirmed it as 46,X?dup(22)(q11.2). Pedigree verification demonstrated that the pregnant woman, her brother and mother had all carried the same duplication. Phenotypic analysis of the affected family members showed classic features of 22q11.2 microduplication syndrome, including hypernasal speech, low nasal bridge, congenital heart disease, and cognitive impairment. A total of 44 cases with full information (including three patients from this pedigree) were included in the analysis. The penetrance of 22q11.2 duplication was approximately 29.5% (13/44), and 52.3% (23/44) of the cases had inherited the variant from a phenotypically normal parent.
CONCLUSION
This study has identified the genetic basis for the woman's recurrent adverse pregnancies and phenotypic abnormalities in her family members. The scoliosis identified in her younger brother has not been previously reported, thereby may enrich the clinical phenotype of this syndrome. For fetuses identified with a 22q11.2 microduplication, detailed fetal imaging is recommended, and genetic counseling should be provided to the couples.
Humans
;
Female
;
Pregnancy
;
Prenatal Diagnosis/methods*
;
Chromosome Duplication/genetics*
;
Male
;
Pedigree
;
DiGeorge Syndrome/diagnosis*
;
Adult
;
Chromosomes, Human, Pair 22/genetics*
;
Abnormalities, Multiple
2.Research advance on the clinical phenotypes and molecular genetic mechanisms of Microcephalic primordial dwarfism.
Chinese Journal of Medical Genetics 2026;43(1):76-80
Primordial dwarfism (PD) refers to a group of monogenic genetic disorders characterized by intrauterine growth restriction (IUGR) and severe, persistent postnatal growth retardation. These diseases have been associated with variants of multiple genes whose products are mainly involved in critical cellular biological processes such as maintenance of genomic stability, DNA damage repair, mRNA splicing regulation, and centrosome function. Variants of such genes can directly impair cell proliferation and developmental potential. With the widespread application of molecular genetic technologies such as high-throughput sequencing, significant progress has been made in the research of PD. This article focuses on the major subtypes of PD, including Seckel syndrome, Microcephalic osteodysplastic primordial dwarfism (MOPD) types I/III, MOPD type II, and Meier-Gorlin syndrome. It has systematically summarized the advances in their clinical phenotypic characteristics, pathogenic genes, and molecular mechanisms, with an aim to deepen the understanding of the essence of growth disorders associated with PD.
Humans
;
Dwarfism/genetics*
;
Microcephaly/genetics*
;
Phenotype
;
Fetal Growth Retardation/genetics*
;
Osteochondrodysplasias/genetics*
;
Growth Disorders
;
Micrognathism
;
Patella/abnormalities*
;
Congenital Microtia
3.Molecular mechanism study of fetal nasal bone aplasia due to a frameshift variant of ARSL gene.
Yuanzhen ZHU ; Ke WU ; Dandan WU
Chinese Journal of Medical Genetics 2026;43(2):102-110
OBJECTIVE:
To analyze the clinical phenotype and pathogenic mechanism of the ARSL gene variant in a fetus with nasal bone aplasia.
METHODS:
A 34-year-old pregnant woman who attended Quzhou Maternal and Child Health Care Hospital on January 3, 2023 was selected as the study subject. Whole exome sequencing (WES) was performed on the fetus. Bioinformatics analysis was carried out to identify and prioritize candidate gene variants, followed by Sanger sequencing for familial validation. A mutant plasmid expression vector was constructed and subsequently transfected into HEK293T cells to preliminarily investigate the pathogenetic mechanism of the identified variant. Additionally, a comprehensive review of literature was conducted to systematically summarize the associated clinical phenotypes. This study was approved by the Medical Ethics Committee of Quzhou Maternal and Child Health Care Hospital (Ethics No.: KY-2023-11).
RESULTS:
WES revealed that the fetus harbored a c.827del (p.L276Rfs*48) variant of the ARSL gene, for which its mother was heterozygous. Based on the guidelines from the American College of Medical Genetics and Genomics (ACMG), the variant was classified as pathogenic(PVS1+PM2_Supporting). In vitro cellular function studies demonstrated that this variant can result in a substantial decrease in the expression of mutant mRNA, thereby preventing the production of normal ARSL protein. Clinical phenotypes resulting from ARSL gene variants exhibited considerable diversity, with nasal hypoplasia being the most common manifestation.
CONCLUSION
The c.827del (p.L276Rfs*48) variant of the ARSL gene can lead to degradation of mRNA via the nonsense-mediated mRNA decay pathway, resulting in reduced levels of ARSL protein. The pathogenetic mechanism underlying the ARSL gene variant may be associated with its haploinsufficiency effect.
Humans
;
Female
;
Pregnancy
;
Adult
;
Frameshift Mutation
;
HEK293 Cells
;
Nasal Bone/abnormalities*
;
Fetus/abnormalities*
;
Exome Sequencing
4.A fetus with Neurodevelopmental disorders with deformed facial features and distal skeletal abnormalities due to a rare variant of ZMIZ1 gene and literature review.
Jinghui ZOU ; Haibo LI ; Lulu YAN
Chinese Journal of Medical Genetics 2026;43(4):295-300
OBJECTIVE:
To investigate the clinical manifestations and genetic etiology of a fetus with Neurodevelopmental disorders with deformed facial features and distal skeletal abnormalities (NEDDFSA).
METHODS:
Clinical data of a NEDDFSA fetus diagnosed at the Affiliated Women and Children's Hospital Affiliated to Ningbo University in March 2025 was selected as the study subject. Whole-exome sequencing (WES) was carried out on the amniotic fluid and parental peripheral blood samples, and candidate variants was verified by Sanger sequencing. The pathogenicity of candidate variant was rated based on guidelines from the American College of Medical Genetics and Genomics (ACMG). This study was approved by the Medical Ethics Committee of the hospital (Ethics No.: EC2023-094).
RESULTS:
At 30 weeks of gestation, the fetus was found to have microcephaly, short femur and intrauterine growth restriction. WES revealed that the fetus harbored a de novo heterozygous frameshift variant c.2633dup (p.Gly879ArgfsTer22) of the ZMIZ1 gene, which was rated as pathogenic (PM2_Supporting+PS2_Supporting+PVS1). Combined with 25 cases from the literature, the main manifestations of patients have included intellectual disability, growth retardation and cranio-limb skeletal dysplasia, albeit without clear genotype-phenotype correlation.
CONCLUSION
The de novo variant c.2633dup (p.Gly879ArgfsTer22) of the ZMIZ1 gene probably underlay the NEDDFSA in this fetus. Genetic testing has enabled accurate prenatal diagnosis and provided evidence for genetic counseling and reproductive guidance of this family.
Humans
;
Female
;
Pregnancy
;
Neurodevelopmental Disorders/genetics*
;
Transcription Factors/genetics*
;
Fetus/abnormalities*
;
Exome Sequencing
;
Prenatal Diagnosis
5.Prenatal diagnosis and genetic counseling of 20 fetuses with 15q11.2 BP1-BP2 microdeletion syndrome.
Meijuan LI ; Xinyou YU ; Lanhua YANG ; Xiaoyan WANG ; Bo WEI
Chinese Journal of Medical Genetics 2025;42(1):64-68
OBJECTIVE:
To explore the clinical phenotype, pregnancy outcome and follow-up of fetuses with 15q11.2BP1-BP2 microdeletions in order to provide a basis for prenatal and reproductive consultation.
METHODS:
From March 2019 to December 2023, 20 fetuses who were diagnosed with 15q11.2BP1-BP2 microdeletion syndrome at the Prenatal Diagnosis Center of General Hospital of Ningxia Medical University were selected as the study subjects. Results of genetic testing and ultrasound examination, outcome of pregnancy, and postnatal follow-up were retrospectively analyzed. This study has been approved by the Ethics Committee of General Hospital of Ningxia Medical University ([2020]0520B).
RESULTS:
None of the 20 fetuses was found to have chromosomal abnormality, whilst all were found to harbor a 15q11.2 BP1-BP2 microdeletion by low-depth whole genome sequencing (CNV-seq). The range of deletions was determined as 0.26 ~ 0.87 Mb, and all were rated as pathogenic CNVs. Three fetuses had abnormal ultrasound findings, including 1 with widened renal pelvis, 1 with agenesis of corpus callosum, and 1 with nuchal fold thickening. Parental verification in 10 couples verified that two fetal deletions were de novo, whilst the remaining eight were inherited from a phenotypically normal parent. Following genetic counseling, three couples had opted to terminate the pregnancy, whilst the remaining 17 had continued with the pregnancy until delivery. The 17 liveborns were followed up for 2 months to 5 years, with no obvious abnormality in growth and development noted.
CONCLUSION
CNV-seq plays an important role in the prenatal diagnosis of 15q11.2 BP1-BP2 microdeletions. Such deletions may not always lead to disease phenotypes. Individualized consultation and long-term follow-up, in combination with intrauterine ultrasound and parental verification are necessary.
Humans
;
Female
;
Pregnancy
;
Chromosomes, Human, Pair 15/genetics*
;
Genetic Counseling
;
Prenatal Diagnosis
;
Chromosome Deletion
;
Adult
;
Fetus/abnormalities*
;
Retrospective Studies
;
Pregnancy Outcome
;
Ultrasonography, Prenatal
;
Genetic Testing
;
DiGeorge Syndrome/diagnosis*
;
Male
6.Clinical feature and genetic analysis of a child with X-linked Opitz G/BBB syndrome caused by nonsense variant in the MID1 gene mediated by mRNA degradation escape.
Yingyu YAN ; Li HE ; Ying YANG ; Duan WANG ; Haiqing ZHANG ; Yanni CHEN
Chinese Journal of Medical Genetics 2025;42(2):219-225
OBJECTIVE:
To explore the genotype-phenotype relationship in a child with Opitz G/BBB syndrome (OS) with mild clinical phenotype.
METHODS:
A child with motor developmental delay as the initial symptom admitted to Xi'an Children's Hospital on June 10, 2021 was selected for this study. Clinical data were collected, and peripheral blood samples were obtained from the child and his mother. Whole exome sequencing (WES) was performed to identify genetic variant in the child. Candidate variant were verified by Sanger sequencing to assess inheritance patterns and pathogenicity. Real-time fluorescence quantitative PCR (RT-qPCR) and Western blot (WB) analyses were conducted to evaluate the effects of the variant on mRNA and protein expression, respectively, using recombinant expression plasmids generated in vitro. This study was approved by the Medical Ethics Committee of Xi'an Children's Hospital (Ethics No. 20240045).
RESULTS:
The child, a 9-month-and-7-day-old boy, presented with a low nasal bridge, hypertelorism, and difficulty sitting independently. Echocardiography revealed an atrial septal defect. WES identified a homozygous variant in the MIDI gene, c.1483C>T (p.R495X), which was confirmed by Sanger sequencing and found to be inherited from the mother.Recombinant expression plasmids were successfully constructed. RT-qPCR analysis showed that the variant significantly reduced MIDI gene mRNA expression, while WB results indicated that the variant led to the production of a truncated protein.
CONCLUSION
The mild clinical phenotype of OS in this child may be attributed to the mRNA degradation escape mechanism induced by the nonsense variant c.1483C>T (p.R495X) in the MIDI gene. These findings provide valuable diagnostic insights for this pedigree and contribute to the understanding of the genotype-phenotype correlation in OS.
Humans
;
Male
;
Infant
;
Transcription Factors/metabolism*
;
Microtubule Proteins/genetics*
;
Craniosynostoses/genetics*
;
Hypospadias/genetics*
;
Codon, Nonsense/genetics*
;
RNA, Messenger/metabolism*
;
Female
;
RNA Stability/genetics*
;
Phenotype
;
Nuclear Proteins/genetics*
;
Ubiquitin-Protein Ligases
;
Esophagus/abnormalities*
;
Hypertelorism
7.Prenatal phenotype and genetic analysis of two fetuses with Bardet-Biedl syndrome.
Lingyi ZHANG ; Zhigang ZHANG ; Xingguang WANG ; Yanyan LI
Chinese Journal of Medical Genetics 2025;42(2):226-231
OBJECTIVE:
To carry out genetic testing on two fetuses with prenatal ultrasound finding of polydactyly and renal abnormalities to determine the underlying causes.
METHODS:
Two fetuses with structural abnormalities detected by prenatal ultrasound at Cangzhou People's Hospital in 2021 were selected as the study subjects. Genomic DNA was extracted from the muscle tissue of the abortus and peripheral blood samples from both parents. Whole-exome sequencing (WES) was conducted on the trio to detect the genetic variants. Quantitative PCR was used to validate the exonic deletions. This study has been approved by the Ethics Committee of Cangzhou People's Hospital (Ethics No.K2020-049).
RESULTS:
Prenatal ultrasound revealed postaxial polydactylies of fingers and toes and slightly enlarged kidneys with increased echogenicity in fetus 1, along with polydactyly of both hands, enlarged kidneys, and enhanced echogenicity of renal parenchyma in fetus 2. Trio-WES analysis revealed that fetus 1 has harbored a pathogenic c.1339G>A variant of the BBS1 gene, along with a heterozygous 426 bp deletion in the 11q13.2 region, which was unreported previously. The deletion has involved exons 10 and 11 of the BBS1 gene. The two variants were inherited from its mother and father, respectively. Fetus 2 was found to harbor a pathogenic c.539G>A variant and a likely pathogenic c.49G>A variant of the BBS10 gene, which were inherited from its mother and father, respectively. The c.49G>A variant has not been documented in databases and the literature.
CONCLUSION
Two rare fetuses with Bardet-Biedl syndrome have been diagnosed. Above finding has expanded the mutational spectrum of this syndrome and has important implications for genetic counseling for the affected families.
Humans
;
Bardet-Biedl Syndrome/diagnostic imaging*
;
Female
;
Pregnancy
;
Fetus/abnormalities*
;
Ultrasonography, Prenatal
;
Phenotype
;
Polydactyly/diagnostic imaging*
;
Exome Sequencing
;
Adult
;
Genetic Testing
;
Male
;
Prenatal Diagnosis
;
Group II Chaperonins/genetics*
;
Microtubule-Associated Proteins
8.Advances in the study of signaling pathways in Global developmental delay /Intellectual disability combined with congenital craniofacial malformation.
Chinese Journal of Medical Genetics 2025;42(2):249-256
Global developmental delay (GDD) and intellectual disability (ID) refer to deficits in cognitive and adaptive functioning that arise during the developmental period. GDD/ID is often accompanied by complex developmental abnormalities, with congenital craniofacial malformations being among the most common, such as craniosynostosis, cleft lip and palate, and congenital tooth agenesis. However, the underlying mechanisms of GDD/ID associated with congenital craniofacial malformations remain unclear. With the increasing number of reported genetic syndromes, genetic factors are emerging as key contributors to the concurrent abnormalities in brain and craniofacial development. Studies have identified Wnt, SHH, FGF, and BMP as classical regulatory molecules in craniofacial development, and their roles have also been closely linked to various stages of brain development. This review focuses on the regulatory roles of Wnt, SHH, FGF, and BMP signaling pathways in brain and craniofacial development, as well as the pathogenic mechanisms underlying their association with GDD/ID and craniofacial malformations. The aim is to provide new insights into the etiology of GDD/ID combined with congenital craniofacial malformations.
Humans
;
Craniofacial Abnormalities/complications*
;
Signal Transduction
;
Developmental Disabilities/metabolism*
;
Intellectual Disability/complications*
;
Animals
;
Hedgehog Proteins/genetics*
;
Fibroblast Growth Factors/genetics*
9.Genetic analysis of a case of Miller-McKusick-Malvaux syndrome type 1 caused by CUL7 gene variant and a literature review.
Liming ZHANG ; Xue WU ; Jianwei YANG ; Hongqi SUN ; Junmei YANG ; Yongxing CHEN
Chinese Journal of Medical Genetics 2025;42(3):343-348
OBJECTIVE:
To explore the clinical features, genetic characteristics in a child with Miller-McKusick-Malvaux syndrome (3MS) type 1 caused by CUL7 gene variant.
METHODS:
A child diagnosed with 3MS type 1 at the Children's Hospital Affiliated to Zhengzhou University in February 2021 was selected as the subject of this study. Peripheral blood samples were collected from the child and her parents for genomic DNA extraction. Whole exome sequencing (WES) was performed on the child, and Sanger sequencing was used to validate the candidate variants and analyze their pathogenicity. A literature search was conducted using the keywords "3M syndrome" in the China National Knowledge Infrastructure, Wanfang Data Knowledge Service Platform, and PubMed databases from inception to December 2024. The clinical data of Chinese children with 3MS reported in the literature were summarized. This study was approved by the Medical Ethics Committee of the Children's Hospital Affiliated to Zhengzhou University (Ethics No. 2024-K-020).
RESULTS:
The child was a 6-year-old and 2-month-old female with facial dysmorphism, skeletal abnormalities, and growth and developmental delay. WES revealed compound heterozygous variants in the CUL7 gene: c.2686G>T (p.E896*) and c.1200delT (p.R401Gfs66). Sanger sequencing confirmed that these two variants were inherited from the child's father and mother, respectively. According to the American College of Medical Genetics and Genomics (ACMG) Standards and Guidelines for the Interpretation of Sequence Variants, c.2686G>T (p.E896) was classified as a pathogenic (PVS1+PM2_Supporting+PM3), and c.1200delT (p.R401Gfs*66) was classified as a likely pathogenic (PVS1+PM2_Supporting). Based on the literature search strategy, 18 relevant articles were identified, including a total of 32 Chinese cases of 3MS, of which 8 were fetuses. A total of 32 Chinese 3MS cases were included in the literature review, of which 8 were fetuses. The majority of these cases carried variants in the CUL7 gene (20/32, 62.5%) and OBSL1 gene (12/32, 37.5%). The main clinical manifestations included intrauterine or postnatal growth and developmental delay (32/32, 100.0%), triangular facies (27/32, 84.3%), and skeletal abnormalities (21/32, 65.6%).
CONCLUSION
The compound heterozygous variants c.2686G>T (p.E896*) and c.1200delT (p.R401Gfs*66) in the CUL7 gene are likely the genetic cause of 3MS type 1 in the child. For children presenting with facial dysmorphism, skeletal abnormalities, and intrauterine or postnatal growth and developmental delay, 3MS should be considered as a differential diagnosis.
Humans
;
Cullin Proteins/genetics*
;
Female
;
Child
;
Limb Deformities, Congenital/genetics*
;
Exome Sequencing
;
Mutation
;
Child, Preschool
;
Dwarfism
;
Muscle Hypotonia
;
Spine/abnormalities*
10.Genetic analysis for a pedigree with Structural heart defects and renal anomalies syndrome caused by variants of TMEM260 gene.
Lulu YAN ; Jinghui ZOU ; Juan CAO ; Jinxiang ZHANG ; Yuxin ZHANG ; Chunxiao HAN ; Yingwen LIU ; Haibo LI
Chinese Journal of Medical Genetics 2025;42(4):460-468
OBJECTIVE:
To explore the genetic characteristics of a fetus affected with Structural heart defects and renal anomalies syndrome (SHDRA).
METHODS:
A pedigree with SHDRA (fetus and the parents) who had visited the Affiliated Women and Children's Hospital of Ningbo University in April 2023 was selected as the study subject. Clinical data of the family were collected. A total of 10 mL of amniotic fluid cells from the fetus and 5 mL of peripheral blood samples from the parents were collected for genomic DNA extraction. Trio whole-exome sequencing (Trio-WES) was performed, and Sanger sequencing was used to validate candidate variants in the family. The identified variants were classified according to the Standards and Guidelines for the Interpretation of Sequence Variants established by the American College of Medical Genetics and Genomics (ACMG) (hereinafter referred to as the "ACMG Guidelines). Relevant research literature on SHDRA in domestic and international databases were searched for literature review. This study was approved by the Affiliated Women and Children's Hospital of Ningbo University (Ethics No. EC2023-094).
RESULTS:
In this family, prenatal ultrasound at 18 weeks of gestation revealed left renal multicystic dysplasia in the fetus. After birth, the infant exhibited an ostium secundum atrial septal defect, patent ductus arteriosus, and left renal multicystic dysplasia. Trio-WES revealed that the fetus had carried c.344dup (p.L116Afs*32) and c.90_104dup (p.Ala31_Ala35dup) compound heterozygous variants in the TMEM260 gene, which were respectively inherited from its father and mother. According to the ACMG guidelines, the c.344dup (p.L116Afs*32) and c.90_104dup (p.Ala31_Ala35dup) variants were classified as pathogenic (PM2_Supporting+PVS1+PP4) and likely pathogenic (PM2_Supporting+PM4+PM3+PP4), respectively. According to the literature search strategy set for this study, a total of 6 literature was retrieved, involving 25 SHDRA patients from 20 families. Together with the patients in this study, there were 14 TMEM260 gene variants, most of which were frameshift variants (7 types) and had located in exons 3, 11 and 13. The main clinical features of SHDRA were congenital heart malformation, renal abnormality and neurodevelopmental abnormality, and there was a lack of genotype-phenotype correlation.
CONCLUSION
The c.344dup (p.L116Afs*32) and c.90_104dup (p.Ala31_Ala35dup) variants of the TMEM260 gene probably underlay the SHDRA in this family. Above finding has provided a basis for clinical diagnosis and genetic counseling for the family.
Humans
;
Female
;
Pedigree
;
Membrane Proteins/genetics*
;
Male
;
Heart Defects, Congenital/genetics*
;
Kidney/abnormalities*
;
Pregnancy
;
Adult
;
Kidney Diseases/congenital*
;
Exome Sequencing
;
Mutation
;
Genetic Testing

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